Motor compressor unit

ABSTRACT

A hermetically sealed motor-compressor unit for a mechanical refrigeration system wherein said unit is suspended within an outer shell. A plurality of pins are spaced about the interior of the shell. The pins engage a portion of the motor-compressor unit when the unit has moved vertically upward a maximum desired amount; the pins prevent any further upward movement. A plurality of feet extend vertically from the lower portion of the unit to prevent the unit from moving excessively in a vertically downward direction within the shell. A cup-shaped member, connected to the interior of the lower portion of the shell has one of the vertically extending feet movably positioned therein to prevent excessive movement of the unit in a diagonal plane within the shell.

United States Patent Abell et al.

[451 Sept. 5, 1972 MOTOR COMPRESSOR UNIT Inventors: Richard S. Abell, Cazenovia; George T. Privon, Camillus, both of NY.

Assignee: Carrier Corporation, Syracuse,

Filed: Dec. 10, 1970 Appl. No.: 96,825

us. Cl. ..4l7/363, 417/902 Int. Cl. ..F04b 17/00, F04b 35/00 Field of Search..... ..417/363, 902

References Cited UNITED STATES PATENTS Primary Examiner-Robert M. Walker Attorney-Harry G. Martin, Jr. and J. Raymond Curtin ABSTRACT A hermetically sealed motor-compressor unit for a mechanical refrigeration system wherein said unit is suspended within an outer shell. A plurality of pins are spaced about the interior of the shell. The pins engage a portion of the motor-compressor unit when the unit has moved vertically upward a maximum desired amount; thepins prevent any further upward movement. A plurality of feet extend vertically from the lower portion of the unit to prevent the unit from moving excessively in a vertically downward direction within the shell. A cup-shaped member, connected to the interior of the lower portion of the shell has one of the vertically extending feet movably positioned therein to prevent excessive movement of the unit in a diagonal plane within the shell.

1 Claim, 3 Drawing Figures PATENTEBSEP" 5 1972 sfifln FIG?) 38 FIG.|

m o1 VENTORS F3 8 8 8 RICHA SABELL FY GEQRGE T. PRIVON ATTORNEY MOTOR COMPRESSOR UNIT BACKGROUND OF THE INVENTION This invention relates to a motor-compressor unit for refrigeration systems, and in particular, to a suspension system for suspending the motor-compressor unit in the shell of a hermetically sealed unit.

The desirability of having an efficient suspension system for a hermetically sealed motor-compressor unit of the type particularly employed in a mechanical refrigeration system is well known to those skilled in unit, once it is installed in a stationary refrigeration installation, it is generally not subjected to severe stresses or shock. However, while the unit is being shipped from its manufacturer to its point of installation, the unit may be subjected to severe shocks which will cause the unit to move quite extensively in its shell, making the various parts of the unit such as the windings of the motor, the lubrication oil pump and the discharge tube, subject to damage.

It is an object of this invention to provide a suspension system for hermetic motor-compressor units specifically operable to prevent damage to the internal parts thereof while preventing transmission of noise or vibration to the outer shell.

SUMMARY OF THE INVENTION This invention relates to a suspension system for a hermetically sealed motor-compressor unit of the type employed in refrigeration systems.

A suspension system in accordance with this invention includes a plurality of support members connected to the interior of the shell and located in spaced relation relative to each other.

A plurality of resilient means such as springs, interconnect each of the support members and the motorcompressor unit, yieldably suspending the unit in the shell.

The suspension system includes a plurality of pins connected to the inner portion of the shell and extending into the interior thereof to prevent the springs from being deformed beyond a predetermined limit, thus preventing various parts of the interior assembly from sharply contacting the interior surface of the shell and thus being damaged. The pins are arranged to contact a portion of the motor-compressor unit when the unit moves vertically upward in the shell a maximum desired distance, preventing any additional vertical movement.

The suspension system also includes a plurality of vertically extending feet, positioned to contact the interior surface of the shell when the motor-compressor unit has moved vertically downward a maximum desired distance, thereby preventing any further downward movement.

The novel suspension system includes a cup-shaped member connected to the lower portion of the interior surface of the shell in which one of the vertically extending feet is movably positioned. The cup-shaped member will contact the foot when the motor-compressor unit moves in a diagonal plane within the shell, preventing excessive movement in such diagonal plane.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 of the drawings shows a vertical sectional view of a hermetically sealed motor-compressor unit illustrating a suspension system in accordance with this invention;

FIG. 2 is a partial sectional view of the motor-compressor unit shown in FIG. 1, illustrating the manner in which the suspension system partially operates; and

FIG. 3 is a side view of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, there is showna hennetically sealed motor-compressor unit embodying the novel suspension system in accordance with this invention. Such motor-compressor unit is typically employed in a mechanical refrigeration system.

The hermetically sealed motor-compressor unit is generally indicated at 10. The unit is housed within a shell generally indicated at 11 having an elliptical cross-sectional shape. Shell 11 is fabricated of a lower shell section 14 and an upper shell section 12 which are welded together. An electric motor generally indicated at 15 and a compressor generally indicated at 17 are disposed within shell 11. Compressor 17 is axially aligned with motor 15 and is disposed therebelow.

Motor 15 includes stator 18 and rotor 20, the rotor being operably connected to drive crankshaft 22. The crankshaft is supported within crankcase 24 of compressor 17.

The crankcase defines the cylinders 27 of the compressor. Enclosing the cylinders are cylinder heads 26 and 28, secured to the crankcase by screws 25. Pistons 46 are disposed within cylinders 27 for reciprocal movement therein. Any desired number of cylinders may be employed. Connecting the pistons to the eccentric portion of crankshaft 22 are connecting rods 42 and wristpins 44. The desired reciprocating movement of the pistons is obtained by rotation of the crankshaft as is obvious to those skilled in the art.

The hennetically sealed motor-compressor unit embodying our invention is typically employed in a mechanical refrigeration system. The refrigerant gas to be compressed, enters into the shell of the compressor via inlet 29. The gas passes through inlet29 and screen 31 and thereafter flows over the windings of motor 15 to cool the same in a manner well known to those skilled in the art. Screen 31 is included to separate any undesirable solid particles that may be entrained in the entering refrigerant gas.

The refrigerant gas, after having cooled the windings of the motor, enters into the compressor portion of the unit via inlet tubes 30 and 32 disposed in the top portion of cylinder heads 26 and 28. The construction of the cylinder heads is more clearly shown in copending application Ser. No. 96,824, filed Dec. 10, 1970, in the names of Douglas J. lngalls and Richard S. Abell.

The refrigerant gas enters each of the cylinders 27 of the compressor via the suction ports (not shown) which are formed in valve plate 52.

The gas, after it is compressed by operation of the piston, enters into an appropriate portion of the cylinder head through discharge ports 48' formed in valve plate 52. Discharge valve 48, connected to plate 52, regulates the flow of gas from the cylinder.

The discharged high pressure gas passes through internal bores of the crankcase in a manner which is more fully explained in copending application Ser. No. 96,792, filed Dec. 10, 1970, in the names of Harvey G. Stenger, George T. Privon and Salvatore Buonocore. Undesirable sound produced by the pulsating nature of the discharge gas is attenuated by passing through the bores of the crankcase. The gas thereafter flows into discharge line 61 which connects with discharge outlet 70 provided for transmitting the compressed gas to the other components of the refrigeration system.

With respect to providing the necessary lubricatio for the unit, oil is stored in sump 39 of the compressor, which is defined by lower shell section 14. Oil pick-up tube 38 extends into the sump, so as to have its inlet below the surface of the oil. The tube is press-fitted into an appropriate aperture formed in the bottom of crankshaft 22. Thrust bearing 41 journals tube 38. During normal operation, rapid rotation of the tube caused by rotation of the crankshaft produces a vacuum at the tubes inlet, causing oil to flow thereinto. Internal bores (not shown) formed eccentrically relative to the centerline of the crankshaft, provide the necessary force for supplying the lubricating oil to the bearing surfaces, such as bearing 43 formed in bearing cap 45. Transverse bores (not shown) communicate with the internal bores of the crankshaft for supplying the oil therefrom to the external bearing surfaces. Grooves 47 are pro vided on the outer surface of crankshaft 22 for the flow of oil to bearings 43 and 49.

A preferred embodiment of a suspension system in accordance with the invention includes spring members 56 provided for yieldably suspending motor-compressor unit in shell 11. Springs 56 are threadably fitted through lugs 54 which are formed integrally with crankcase 24. Support members 58 are connected to the interior of the upper and lower portion of the shell and are spaced uniformly therearound. Each of the supports 58 engages an associated spring in the manner shown in FIG. 3.

As shown in FIG. 1, pins 62 are connected to the upper shell 12 and extend toward the interior portion thereof. As illustrated in FIG. 2, pins 62 are designed to contact an appropriate portion of the motor-compressor unit, for example the upper surface of cylinder heads 26 and 28, when the springs have been deformed to their predetermined outer limit upon the unit moving vertically upward within the shell upon its having been subjected to a severe shock. As shown in FIG. 2, when the unit has moved upwardly so that cylinder head 28 contacts pin 62, there will still be a clearance between the windings of stator 18 and the interior surface of upper shell 12.

The suspension system includes vertically extending feet 64 which are provided for contacting the interior surface of lower shell 14 when the springs have been deformed by vertically downward movement of the motor-compressor unit a maximum desired distance.

Pins 62 and feet 64 operate as stops and prevent the springs from being deformed beyond their elastic limit. The stops also serve to prevent any of the parts of the compressor, such as oil pick-up tube 38, or the windings of the rotor or stator, from contacting the interior surfaces of the compressor shell by preventing any movement in a vertical direction beyond a maximum predetermined amount.

To further prevent any excessive movement, whereby parts may be damaged, cup-shaped member 66 is connected to the interior surface of the lower shell. Member 66 has one of the vertically extending feet, for example foot 64, movably extending thereinto. The maximum amount of upward vertical movement of the compressor unit as permitted by pins 62, will not be so excessive as to have foot 64' withdrawn from the interior of the cup-shaped member 66.

If the motor-compressor unit were subjected to a force which would operate to move the unit in a diagonal plane within the interior of the housing, cupshaped member 66 cooperates with foot 64' to limit such movement. Thus damage to the internal parts of the motor-compressor unit is prevented.

The novel suspension system in accordance with our invention limits movement of the motor-compressor unit within the shell so as to prevent irreparable damage of the parts.

While we have described and illustrated a preferred embodiment, the invention is not limited thereto but may be otherwise embodied within the scope of the following claims.

We claim:

1. A hermetically sealed motor-compressor unit of the type employed in a mechanical refrigeration system having a suspension system for mounting the unit in its shell comprising:

A. a plurality of paired support members associated with said shells;

B. spring means adapted for engagement with support lugs formed on the motor-compressor unit, each of the spring means projecting above and below a support lug for engagement with both members of the support member pair associated therewith to yieldably support said member in said shell;

C. a plurality of radially, inwardly extending pin means associated with said shell, arranged to contact a portion of said motor-compressor unit when said motor compressor unit has moved vertically upward to its maximum desired position;

D. a plurality of vertically extending feet connected to the lower portion of the motor-compressor unit for contacting the inner surface of the bottom of said shell to prevent any further downward movement when the motor-compressor unit has moved vertically downward a maximum predetermined amount; and

E. a substantially cup-shaped member connected to the inner portion of said shell and arranged so that one of said vertically extending feet is vertically movable therein to prevent the motor-compressor unit from moving beyond a predetermined amount in a diagonal plane in said shell. 

1. A hermetically sealed motor-compressor unit of the type employed in a mechanical refrigeration system having a suspension system for mounting the unit in its shell comprising: A. a plurality of paired support members associated with said shells; B. spring means adapted for engagement with support lugs formed on the motor-compressor unit, each of the spring means projecting above and below a support lug for engagement with both members of the support member pair associated therewith to yieldably support said member in said shell; C. a plurality of radially, inwardly extending pin means associated with said shell, arranged to contact a portion of said motor-compressor unit when said motor compressor unit has moved vertically upward to its maximum desired position; D. a plurality of vertically extending feet connected to the lower portion of the motor-compressor unit for contacting the inner surface of the bottom of said shell to prevent any further downward movement when the motor-compressor unit has moved vertically downward a maximum predetermined amount; and E. a substantially cup-shaped member connected to the inner portion of said shell and arranged so that one of said vertically extending feet is vertically movable therein to prevent the motor-compressor unit from moving beyond a predetermined amount in a diagonal plane in said shell. 